Katan, 24, officially becomes a West Ham player on January 1st when the transfer window re-opens and Hammers boss Alan Pardew was delighted at securing Yaniv’s services.
He told the official site, “We're delighted to have secured the signature of Yaniv Katan and we expect him to become an important member of our squad.
“The chance to sign a player of his quality was a great opportunity for West Ham United and one that we couldn't miss.
“His signing represents a good deal for the club, and will give us the resources to further add to the squad when the transfer window opens in January.”